/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "NetworkLoadMetrics.h"
#include "ResourceLoaderIdentifier.h"
#include "ScriptExecutionContextIdentifier.h"
#include "ThreadableLoader.h"
#include "ThreadableLoaderClient.h"
#include "ThreadableLoaderClientWrapper.h"
#include <wtf/text/WTFString.h>

namespace WebCore {

class ContentSecurityPolicy;
class DocumentThreadableLoader;
class ResourceError;
class ResourceRequest;
class SecurityOrigin;
class WorkerOrWorkletGlobalScope;
class WorkerLoaderProxy;

class WorkerThreadableLoader : public RefCounted<WorkerThreadableLoader>, public ThreadableLoader {
    WTF_MAKE_FAST_ALLOCATED_WITH_HEAP_IDENTIFIER(Loader);
public:
    static void loadResourceSynchronously(WorkerOrWorkletGlobalScope&, ResourceRequest&&, ThreadableLoaderClient&, const ThreadableLoaderOptions&);
    static Ref<WorkerThreadableLoader> create(WorkerOrWorkletGlobalScope& WorkerOrWorkletGlobalScope, ThreadableLoaderClient& client, const String& taskMode, ResourceRequest&& request, const ThreadableLoaderOptions& options, const String& referrer)
    {
        return adoptRef(*new WorkerThreadableLoader(WorkerOrWorkletGlobalScope, client, taskMode, WTFMove(request), options, referrer));
    }

    ~WorkerThreadableLoader();

    void cancel() override;

    bool done() const { return m_workerClientWrapper->done(); }

    void notifyIsDone(bool isDone);

    using RefCounted<WorkerThreadableLoader>::ref;
    using RefCounted<WorkerThreadableLoader>::deref;

protected:
    void refThreadableLoader() override { ref(); }
    void derefThreadableLoader() override { deref(); }

private:
    // Creates a loader on the main thread and bridges communication between
    // the main thread and the worker context's thread where WorkerThreadableLoader runs.
    //
    // Regarding the bridge and lifetimes of items used in callbacks, there are a few cases:
    //
    // all cases. All tasks posted from the worker context's thread are ok because
    //    the last task posted always is "mainThreadDestroy", so MainThreadBridge is
    //    around for all tasks that use it on the main thread.
    //
    // case 1. worker.terminate is called.
    //    In this case, no more tasks are posted from the worker object's thread to the worker
    //    context's thread -- WorkerOrWorkletGlobalScopeProxy implementation enforces this.
    //
    // case 2. xhr gets aborted and the worker context continues running.
    //    The ThreadableLoaderClientWrapper has the underlying client cleared, so no more calls
    //    go through it. All tasks posted from the worker object's thread to the worker context's
    //    thread contain the RefPtr<ThreadableLoaderClientWrapper> object, so the
    //    ThreadableLoaderClientWrapper instance is there until all tasks are executed.
    class MainThreadBridge final : public ThreadableLoaderClient {
        WTF_MAKE_FAST_ALLOCATED_WITH_HEAP_IDENTIFIER(Loader);
        WTF_OVERRIDE_DELETE_FOR_CHECKED_PTR(MainThreadBridge);
    public:
        // All executed on the worker context's thread.
        MainThreadBridge(ThreadableLoaderClientWrapper&, WorkerLoaderProxy*, ScriptExecutionContextIdentifier, const String& taskMode, ResourceRequest&&, const ThreadableLoaderOptions&, const String& outgoingReferrer, WorkerOrWorkletGlobalScope&);
        virtual ~MainThreadBridge();

        void cancel();
        void destroy();
        void computeIsDone();

    private:
        // Executed on the worker context's thread.
        void clearClientWrapper();
        RefPtr<ThreadableLoaderClientWrapper> protectedWorkerClientWrapper() const;

        // All executed on the main thread.
        void didSendData(unsigned long long bytesSent, unsigned long long totalBytesToBeSent) override;
        void didReceiveResponse(ScriptExecutionContextIdentifier, ResourceLoaderIdentifier, const ResourceResponse&) override;
        void didReceiveData(const SharedBuffer&) override;
        void didFinishLoading(ScriptExecutionContextIdentifier, ResourceLoaderIdentifier, const NetworkLoadMetrics&) override;
        void didFail(ScriptExecutionContextIdentifier, const ResourceError&) override;
        void didFinishTiming(const ResourceTiming&) override;
        void notifyIsDone(bool isDone) final;

        // Only to be used on the main thread.
        RefPtr<DocumentThreadableLoader> m_mainThreadLoader;
        bool m_loadingFinished { false };

        // ThreadableLoaderClientWrapper is to be used on the worker context thread.
        // The ref counting is done on either thread.
        RefPtr<ThreadableLoaderClientWrapper> m_workerClientWrapper;

        // May be used on either thread.
        WorkerLoaderProxy* m_loaderProxy; // FIXME: Use a smart pointer.

        // For use on the main thread.
        String m_taskMode;
        ResourceLoaderIdentifier m_workerRequestIdentifier;
        NetworkLoadMetrics m_networkLoadMetrics;
        ScriptExecutionContextIdentifier m_contextIdentifier;
    };

    WorkerThreadableLoader(WorkerOrWorkletGlobalScope&, ThreadableLoaderClient&, const String& taskMode, ResourceRequest&&, const ThreadableLoaderOptions&, const String& referrer);

    void computeIsDone() final;

    Ref<ThreadableLoaderClientWrapper> m_workerClientWrapper;
    MainThreadBridge& m_bridge; // FIXME: Use a smart pointer.
};

} // namespace WebCore
